New technology for microscopic inspection of solar-grade silicon wafer velvet

After 50 years of development of solar cells, the photovoltaic industry (solar power generation industry) finally crossed the historical watershed in 2004 and officially entered the take-off stage. With the German government's announcement of the Renewable Energy Law on January 1, 2004, solar energy was selected as the main alternative energy source, and practical measures were taken to popularize solar power generation (the government not only subsidized the installation of solar modules by the private sector, but also guaranteed to buy back electricity at a certain rate), the solar cell industry officially entered a period of rapid growth in demand.

With the continuous development and improvement of polysilicon, silicon wafers, and solar panel processes, the photovoltaic industry has higher and higher requirements for silicon wafer quality testing. Because foreign optical testing is too expensive, it is a huge expense for non-raw material manufacturers, and it is necessary to test imported silicon wafers. In response to this situation, Shanghai Cewei Optoelectronics Technology Co., Ltd. has developed a detection system for solar silicon wafers. The system can analyze the microscopic morphology distribution of the "pyramid" of solar cell silicon wafers and the defects of silicon wafer velvet. For example, silicon wafer inspection microscopes can observe dislocations, scratches, and edge collapse that are difficult to observe with the naked eye; they can also analyze the impurities and residue components of silicon wafers. Impurities include: particles, organic impurities, inorganic impurities, metal ions, silicon powder dust, etc., which cause the silicon wafers after grinding to be prone to flowery, blue, black, etc., making the grinding unqualified. It is one of the essential detection instruments in the production process of solar cell silicon wafers. The LW300MT silicon chip inspection microscope produced by Shanghai Cewei is suitable for microscopic observation of solar cell silicon wafers. The instrument is equipped with a stage with a large moving range, an epi-illuminator, a long working distance plan achromatic objective lens, and a wide field of view eyepiece. It has clear images and good contrast. It is also equipped with a polarizing device and a high-pixel digital camera. The instrument is equipped with a dark-field objective lens, which makes the image clearer when observing silicon wafers. It is an ideal instrument for detecting the microscopic morphology distribution of the "pyramid" of solar cell silicon wafers and defect analysis of silicon wafers.